JPH07151965A - Attachment lens - Google Patents

Attachment lens

Info

Publication number
JPH07151965A
JPH07151965A JP32139993A JP32139993A JPH07151965A JP H07151965 A JPH07151965 A JP H07151965A JP 32139993 A JP32139993 A JP 32139993A JP 32139993 A JP32139993 A JP 32139993A JP H07151965 A JPH07151965 A JP H07151965A
Authority
JP
Japan
Prior art keywords
lens
group
attachment
refractive power
positive
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP32139993A
Other languages
Japanese (ja)
Inventor
Takeshi Nishimura
威志 西村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to JP32139993A priority Critical patent/JPH07151965A/en
Publication of JPH07151965A publication Critical patent/JPH07151965A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To attach the attachment lens to the image surface side of a photographing lens so that it is freely attached and detached and to correct a photographing field angle by constituting it of a positive refractive power lens group and a negative refractive power lens group whose constituting number of sheets is specified and specifying the enlargement magnification thereof. CONSTITUTION:The attachment lens AL having negative refractive power for changing a mount which is attached to the image surface side of the photographing lens so as to be freely attached and detached and can be attached to a camera whose effective field angle size is smaller than that of the photographing lens is constituted of a first group L1 whose refractive power is positive and a second group L2 whose refractive power is negative. Then, the first group L1 is constituted of the single positive lens and the second group L2 is constituted of the bonded lens with the negative lens and the positive lens joined. When the enlargement magnification of the lens AL is defined as beta, the condition of 1<beta<1.1 is satisfied. Thus, a distance between the flange of the photographing lens and an image forming surface is extended and the various kinds of aberration can be excellently corrected. Besides, the F-number of the photographing lens is maintained to be almost constant.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明はアタッチメントレンズに
関し、特に一眼レフカメラ等のレンズ交換が可能なカメ
ラにおいて撮影レンズの像面側に装着することにより、
該撮影レンズの有効画角サイズより小さい有効画角サイ
ズのカメラに装着可能とするマウント変換のためのアタ
ッチメントレンズに関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attachment lens, and in particular, in an interchangeable lens camera such as a single-lens reflex camera, it is mounted on the image side of a photographing lens,
The present invention relates to an attachment lens for mount conversion that can be mounted on a camera having an effective angle of view smaller than the effective angle of view of the taking lens.

【0002】[0002]

【従来の技術】従来より、撮影レンズとカメラ本体との
間に装着するマウント交換のためのアタッチメントレン
ズは種々と提案されている。例えば35mmフィルムS
LRカメラ用の撮影レンズをビデオカメラ等の有効画角
サイズが小さい光学装置に装着可能とし、かつ有効画角
サイズの相違によって生ずる画角の変動、つまり望遠側
へシフトすることを抑える働きを有したものが提案され
ている。
2. Description of the Related Art Heretofore, various attachment lenses for mounting a mount mounted between a photographing lens and a camera body have been proposed. For example, 35mm film S
A shooting lens for an LR camera can be attached to an optical device such as a video camera having a small effective angle of view, and has a function of suppressing a change in the angle of view caused by a difference in the effective angle of view, that is, a shift to the telephoto side. What has been done is proposed.

【0003】一般にこの種のマウント変換のためのアタ
ッチメントレンズは光学性質上、正の屈折力を有してい
る。
Generally, an attachment lens for this type of mount conversion has a positive refracting power in terms of optical properties.

【0004】[0004]

【発明が解決しようとする課題】一般に撮影レンズをそ
の撮影レンズが有する有効画角サイズより比較的小さ
い、例えば0.7〜0.9倍程度の有効画角サイズのカ
メラに装着しようとした場合、バックフォーカスや収差
補正等の制約がある。このためアタッチメントレンズを
正の屈折力にすることが困難となり、又アタッチメント
レンズが大型化してくるという問題がある。
Generally, when an attempt is made to attach the taking lens to a camera having an effective angle of view size which is relatively smaller than the effective angle of view of the taking lens, for example, 0.7 to 0.9 times. There are restrictions such as back focus and aberration correction. Therefore, it becomes difficult to make the attachment lens have a positive refractive power, and there is a problem that the attachment lens becomes large.

【0005】又画角の補正を意図しない場合、撮影レン
ズのフランジから結像面までの距離、即ちフランジバッ
クFbのカメラ用に設計された撮影レンズをフランジバ
ックFbより比較的小さいフランジバックfbのカメラ
に使用する場合がある。このためにはフランジバックの
差に相当する差分Δ=(Fb−fb)を空気補正すれば
良い。
If the angle of view is not intended to be corrected, the distance from the flange of the taking lens to the image plane, that is, the taking lens designed for a camera having a flange back Fb is designed to have a smaller flange back fb than the flange back Fb. May be used for cameras. For this purpose, the difference Δ = (Fb−fb) corresponding to the difference in flange back may be corrected by air.

【0006】しかしながら差分Δがある程度大きくない
と、撮影レンズのフランジバックFbとフランジバック
fbとのカメラのマウントとの間隔である差分Δを空気
補正するようにしたアタッチメントはメカ的な要因によ
りその実現が大変困難になってくる。
However, if the difference Δ is not large to some extent, an attachment for correcting the difference Δ, which is the distance between the flange back Fb and the flange back fb of the photographing lens and the mount of the camera, is realized by a mechanical factor. Becomes very difficult.

【0007】本発明は撮影レンズの像面側に着脱可能に
装着し、該撮影レンズのフランジから結像面までの距離
を延長し、かつ諸収差を良好に補正すると共に該撮影レ
ンズのFナンバーを略一定に維持しつつ、倍率1.0〜
1.1程度を有するアタッチメントレンズの提供を目的
とする。
According to the present invention, the photographic lens is detachably attached to the image side, the distance from the flange of the photographic lens to the image plane is extended, and various aberrations are satisfactorily corrected. Magnification of 1.0 to
The purpose is to provide an attachment lens having a thickness of about 1.1.

【0008】[0008]

【課題を解決するための手段】本発明のアタッチメント
レンズは、撮影レンズの像面側に着脱自在に装着し、該
撮影レンズの有効画角サイズより小さい有効画角サイズ
のカメラに装着可能なマウント変換のための負の屈折力
のアタッチメントレンズであって該アタッチメントレン
ズは正の屈折力の第1群と負の屈折力の第2群より成
り、該第1群は正レンズ1枚から成り、該第2群は負レ
ンズと正レンズの2枚のレンズから成り、該アタッチメ
ントレンズの拡大倍率をβとするとき、 1<β<1.1 ・・・・・ (1) なる条件を満足することを特徴としている。
The attachment lens of the present invention is a mount which is detachably attached to the image side of a taking lens and is attachable to a camera having an effective angle of view smaller than the effective angle of view of the taking lens. An attachment lens of negative refractive power for conversion, the attachment lens comprising a first group of positive refractive power and a second group of negative refractive power, the first group consisting of one positive lens, The second group consists of two lenses, a negative lens and a positive lens, and when the magnification of the attachment lens is β, the condition 1 <β <1.1 (1) is satisfied. It is characterized by that.

【0009】[0009]

【実施例】図1〜図4は本発明のアタッチメントレンズ
ALの後述する数値実施例1〜4のレンズ断面図であ
る。
1 to 4 are lens cross-sectional views of Numerical Examples 1 to 4 to be described later of the attachment lens AL of the present invention.

【0010】図9は本発明のアタッチメントレンズを装
着する例として選択した公知のガウス型レンズより成る
撮影レンズMLのレンズ断面図である。
FIG. 9 is a lens sectional view of a taking lens ML composed of a known Gauss type lens selected as an example of mounting the attachment lens of the present invention.

【0011】尚本発明のアタッチメントレンズは図9に
示す撮影レンズの他にどのようなタイプの撮影レンズに
も適用可能である。
The attachment lens of the present invention can be applied to any type of taking lens other than the taking lens shown in FIG.

【0012】本発明のアタッチメントレンズALは正の
屈折力の第1群L1と負の屈折力の第2群L2より成っ
ている。そして第1群L1は単一の正レンズより成り、
第2群L2は負レンズと正レンズを接合した貼り合わせ
レンズより成っている。
The attachment lens AL of the present invention comprises a first lens unit L1 having a positive refractive power and a second lens unit L2 having a negative refractive power. The first unit L1 is composed of a single positive lens,
The second unit L2 is composed of a cemented lens in which a negative lens and a positive lens are cemented.

【0013】一般に撮影レンズは単体でカメラに装着し
て使用されるため、それ自体で収差補正がなされてい
る。それ故にアタッチメントレンズを撮影レンズの像面
側に装着したとき全体的に良好な性能を維持するために
はアタッチメントレンズ自体で良好なる収差補正をして
おく必要がある。
Generally, since the taking lens is used by being attached to the camera by itself, the aberration is corrected by itself. Therefore, in order to maintain good performance as a whole when the attachment lens is mounted on the image plane side of the taking lens, it is necessary to perform good aberration correction on the attachment lens itself.

【0014】本実施例では撮影レンズにアタッチメント
レンズを装着し、該撮影レンズの有効画角サイズより比
較的小さい有効画角サイズのカメラに使用するようにし
ている。このためアタッチメントレンズを装着したとき
には全系の撮影画角が減少し、望遠側へシフトする。こ
のときアタッチメントレンズの倍率を大きくする程、全
系の望遠側へのシフト量も増大する。
In this embodiment, an attachment lens is attached to the taking lens so that the taking lens is used in a camera having an effective angle of view size relatively smaller than that of the taking lens. For this reason, when the attachment lens is attached, the shooting angle of view of the entire system decreases and shifts to the telephoto side. At this time, as the magnification of the attachment lens is increased, the shift amount of the entire system toward the telephoto side also increases.

【0015】そこで本実施例ではアタッチメントレンズ
の倍率βが1<β<1.1なる条件式を満足することを
前提として画角の減少を抑えると同時に、Fナンバーの
変動を抑えている。
Therefore, in the present embodiment, it is assumed that the magnification β of the attachment lens satisfies the conditional expression 1 <β <1.1, and the reduction of the angle of view is suppressed and the fluctuation of the F number is suppressed.

【0016】又アタッチメントレンズを正の屈折力の第
1群と負の屈折力の第2群で構成し、アタッチメントレ
ンズ単独で負の屈折力を有するようにしている。これに
より撮影レンズに装着したときに全系の収差補正を良好
に達成している。
The attachment lens is composed of a first group having a positive refracting power and a second group having a negative refracting power, and the attachment lens alone has a negative refracting power. As a result, the aberration correction of the entire system is satisfactorily achieved when it is attached to the taking lens.

【0017】本発明の目的とするアタッチメントレンズ
は以上の諸条件を満足することにより達成されるが、更
に撮影レンズに装着したときの全系の諸収差の変動を少
なくし、所定のバックフォーカスを有し、高い光学性能
を維持するには次の諸条件を満足するのが良い。
The attachment lens which is the object of the present invention can be achieved by satisfying the above-mentioned various conditions. Further, the variation of various aberrations of the entire system when attached to the taking lens is reduced and a predetermined back focus is achieved. In order to maintain high optical performance, it is better to satisfy the following conditions.

【0018】(1−1)前記第1群と第2群の焦点距離
を各々f1,f2、該第1群と第2群の面間隔をD1
2、前記アタッチメントレンズの焦点距離をfaとした
とき、 1.2<|f1 /f2|<1.6 ・・・・・ (2) 0.002<|D12/fa|<0.01 ・・・・・ (3) なる条件を満足することである。
(1-1) The focal lengths of the first group and the second group are f1 and f2, respectively, and the surface distance between the first group and the second group is D1.
2. When the focal length of the attachment lens is fa, 1.2 <| f1 / f2 | <1.6 (2) 0.002 <| D12 / fa | <0.01 (3) To satisfy the following condition.

【0019】条件式(2)は第1群と第2群の屈折力の
比に関し、所定のバックフォーカスを維持しつつ、全系
の諸収差をバランス良く補正するためのものである。
Conditional expression (2) relates to the ratio of the refracting powers of the first group and the second group, and is for correcting various aberrations of the entire system in a well-balanced manner while maintaining a predetermined back focus.

【0020】条件式(2)の下限値を越えると第1群の
正の屈折力が強くなり過ぎるため、所定のバックフォー
カスを確保するのが困難になり、そのために第2群の負
の屈折力を強くすれば諸収差のバランスが崩れ、収差補
正が困難になる。又上限値を越えるとバックフォーカス
は十分確保することができるものの、諸収差のバランス
が崩れ、特にペッツバール和が負の方向に増大し、像面
特性が悪化するので良くない。
If the lower limit of conditional expression (2) is exceeded, the positive refracting power of the first lens group will become too strong, and it will be difficult to secure a predetermined back focus. If the force is increased, the balance of various aberrations will be lost and it will be difficult to correct aberrations. On the other hand, when the value exceeds the upper limit, the back focus can be sufficiently secured, but the balance of various aberrations is disturbed, especially the Petzval sum increases in the negative direction, and the image surface characteristics deteriorate, which is not preferable.

【0021】条件式(3)は第1群と第2群との面間隔
を適切に設定し、主に球面収差を良好に補正するための
ものである。
Conditional expression (3) is for properly setting the surface distance between the first group and the second group, and mainly for favorably correcting spherical aberration.

【0022】条件式(3)の下限値を越えると球面収差
がアンダーになり、良好なる収差補正が困難になる。又
上限値を越えると所定の長さのバックフォーカスの確保
が困難になると同時に球面収差がオーバーとなり、良好
なる収差補正が困難になる。
If the lower limit of conditional expression (3) is exceeded, spherical aberration will become under, and satisfactory aberration correction will become difficult. On the other hand, when the value exceeds the upper limit, it becomes difficult to secure a back focus of a predetermined length, and at the same time spherical aberration becomes excessive, which makes it difficult to correct aberrations satisfactorily.

【0023】(1−2)アタッチメントレンズを構成す
る正レンズの材質の平均屈折率と平均アッベ数をそれぞ
れnp ,νp 、負レンズの材質の屈折率とアッベ数をそ
れぞれnn ,νn とするとき、 1.0<n /n <1.2 ・・・・・ (4) 1.0<ν /ν <1.2 ・・・・・・(5) なる条件を満足することである。
(1-2) The average refractive index and the average Abbe number of the material of the positive lens constituting the attachment lens are n p and ν p , respectively, and the refractive index and the Abbe number of the material of the negative lens are n n and ν n , respectively. Then, the condition 1.0 <n n / n p <1.2 (4) 1.0 <ν n / ν p <1.2 (5) To be satisfied.

【0024】条件式(4),(5)はアタッチメントレ
ンズを構成する各レンズの材質の屈折率とアッベ数を適
切に設定し、主に像面弯曲と色収差を良好に補正するた
めのものである。
Conditional expressions (4) and (5) are used to properly set the refractive index and Abbe number of the material of each lens constituting the attachment lens, and mainly to favorably correct the field curvature and chromatic aberration. is there.

【0025】条件式(4)の下限値を越えるとペッツバ
ール和が負の方向に増大し、像面特性が悪化してくる。
又上限値を越えると像面特性が補正過剰となると共にコ
マ収差や色収差を良好に補正するのが困難となる。
If the lower limit of conditional expression (4) is exceeded, the Petzval sum increases in the negative direction, degrading the image plane characteristics.
If the upper limit is exceeded, the image plane characteristics will be overcorrected, and it will be difficult to favorably correct coma and chromatic aberration.

【0026】条件式(5)の下限値を越えると軸上色収
差が補正不足となり、又上限値を越えると倍率色収差が
補正不足となるので良くない。
If the lower limit of conditional expression (5) is exceeded, axial chromatic aberration will be undercorrected, and if the upper limit is exceeded, lateral chromatic aberration will be undercorrected, which is not good.

【0027】次に本発明のアタッチメントレンズとそれ
を装着する図9の撮影レンズの数値実施例を示す。数値
実施例においてRiは物体側より順に第i番目のレンズ
面の曲率半径、Diは物体側より第i番目のレンズ厚及
び空気間隔、Niとνiは各々物体側より順に第i番目
のレンズのガラスの屈折率とアッベ数である。
Next, numerical examples of the attachment lens of the present invention and the taking lens of FIG. In the numerical examples, Ri is the radius of curvature of the i-th lens surface in order from the object side, Di is the i-th lens thickness and air gap from the object side, and Ni and νi are respectively from the object side of the i-th lens. The refractive index of glass and the Abbe number.

【0028】又前述の各条件式と数値実施例における諸
数値との関係を表−1に示す。
Table 1 shows the relationship between the above-mentioned conditional expressions and various numerical values in the numerical examples.

【0029】 アタッチメントレンズ 〈数値実施例1〉 R 1= 2.13 D 1= 0.05 N 1=1.59551 ν 1= 39.2 R 2=-17.30 D 2= 0.06 R 3= -7.19 D 3= 0.03 N 2=1.77250 ν 2= 49.6 R 4= 0.81 D 4= 0.09 N 3=1.51742 ν 3= 52.4 R 5= 14.60 〈数値実施例2〉 R 1= 2.06 D 1= 0.05 N 1=1.59551 ν 1= 39.2 R 2=107.60 D 2= 0.05 R 3=-14.87 D 3= 0.05 N 2=1.77250 ν 2= 49.6 R 4= 0.81 D 4= 0.08 N 3=1.51742 ν 3= 52.4 R 5= 12.02 〈数値実施例3〉 R 1= 2.89 D 1= 0.06 N 1=1.54814 ν 1= 45.8 R 2= -4.64 D 2= 0.04 R 3= -3.96 D 3= 0.05 N 2=1.69680 ν 2= 55.5 R 4= 0.95 D 4= 0.08 N 3=1.51112 ν 3= 60.5 R 5= 13.16 〈数値実施例4〉 R 1= 2.18 D 1= 0.07 N 1=1.56732 ν 1= 42.8 R 2= -2.40 D 2= 0.03 R 3= -2.20 D 3= 0.08 N 2=1.69680 ν 2= 55.5 R 4= 0.66 D 4= 0.09 N 3=1.51112 ν 3= 60.5 R 5= 4.63 撮影レンズ F= 1.00000 fno=1:1.4 2ω= 46.0° R 1= 0.973 D 1= 0.12 N 1=1.81600 ν 1= 46.6 R 2= 4.245 D 2= 0.00 R 3= 0.484 D 3= 0.09 N 2=1.69680 ν 2= 55.5 R 4= 0.840 D 4= 0.03 R 5= 1.124 D 5= 0.05 N 3=1.66446 ν 3= 35.8 R 6= 0.332 D 6= 0.32 R 7= -0.355 D 7= 0.04 N 4=1.71736 ν 4= 29.5 R 8= 2.899 D 8= 0.13 N 5=1.75500 ν 5= 52.3 R 9= -0.625 D 9= 0.00 R10= -1.999 D10= 0.08 N 6=1.78800 ν 6= 47.4 R11= -0.636 D11= 0.00 R12= 3.291 D12= 0.06 N 7=1.77250 ν 7= 49.6 R13= -2.183 Attachment Lens <Numerical Example 1> R 1 = 2.13 D 1 = 0.05 N 1 = 1.59551 ν 1 = 39.2 R 2 = -17.30 D 2 = 0.06 R 3 = -7.19 D 3 = 0.03 N 2 = 1.77250 ν 2 = 49.6 R 4 = 0.81 D 4 = 0.09 N 3 = 1.51742 ν 3 = 52.4 R 5 = 14.60 <Numerical Example 2> R 1 = 2.06 D 1 = 0.05 N 1 = 1.59551 ν 1 = 39.2 R 2 = 107.60 D 2 = 0.05 R 3 = -14.87 D 3 = 0.05 N 2 = 1.77250 ν 2 = 49.6 R 4 = 0.81 D 4 = 0.08 N 3 = 1.51742 ν 3 = 52.4 R 5 = 12.02 <Numerical Example 3> R 1 = 2.89 D 1 = 0.06 N 1 = 1.54814 ν 1 = 45.8 R 2 = -4.64 D 2 = 0.04 R 3 = -3.96 D 3 = 0.05 N 2 = 1.69680 ν 2 = 55.5 R 4 = 0.95 D 4 = 0.08 N 3 = 1.51112 ν 3 = 60.5 R 5 = 13.16 <Numerical Example 4> R 1 = 2.18 D 1 = 0.07 N 1 = 1.56732 ν 1 = 42.8 R 2 = -2.40 D 2 = 0.03 R 3 = -2.20 D 3 = 0.08 N 2 = 1.69680 ν 2 = 55.5 R 4 = 0.66 D 4 = 0.09 N 3 = 1.51112 ν 3 = 60.5 R 5 = 4.63 Shooting lens F = 1.00000 fno = 1: 1.4 2ω = 46.0 ° R 1 = 0.973 D 1 = 0.12 N 1 = 1.81600 ν 1 = 46.6 R 2 = 4.245 D 2 = 0.00 R 3 = 0.484 D 3 = 0.09 N 2 = 1.69680 ν 2 = 55.5 R 4 = 0.840 D 4 = 0.03 R 5 = 1.124 D 5 = 0.05 N 3 = 1.66446 ν 3 = 35.8 R 6 = 0.332 D 6 = 0.32 R 7 = -0.355 D 7 = 0.04 N 4 = 1.71736 ν 4 = 29.5 R 8 = 2.899 D 8 = 0.13 N 5 = 1.75500 ν 5 = 52.3 R 9 = -0.625 D 9 = 0.00 R10 = -1.999 D10 = 0.08 N 6 = 1.78800 ν 6 = 47.4 R11 = -0.636 D11 = 0.00 R12 = 3.291 D12 = 0.06 N 7 = 1.77250 ν 7 = 49.6 R13 = -2.183

【0030】[0030]

【表1】 [Table 1]

【0031】[0031]

【発明の効果】本発明によれば以上のように、撮影レン
ズの像面側に着脱可能に装着し、該撮影レンズのフラン
ジから結像面までの距離を延長し、かつ諸収差を良好に
補正すると共に該撮影レンズのFナンバーを略一定に維
持しつつ、倍率1.0〜1.1程度を有するアタッチメ
ントレンズを達成することができる。
As described above, according to the present invention, the image pickup lens is detachably attached to the image side, the distance from the flange of the image pickup lens to the image forming surface is extended, and various aberrations are improved. It is possible to achieve an attachment lens having a magnification of about 1.0 to 1.1 while performing the correction and maintaining the F number of the taking lens substantially constant.

【図面の簡単な説明】[Brief description of drawings]

【図1】 本発明のアタッチメントレンズの数値実施例
1のレンズ断面図
FIG. 1 is a lens sectional view of Numerical Example 1 of an attachment lens of the present invention.

【図2】 本発明のアタッチメントレンズの数値実施例
2のレンズ断面図
FIG. 2 is a lens cross-sectional view of Numerical Example 2 of the attachment lens of the present invention.

【図3】 本発明のアタッチメントレンズの数値実施例
3のレンズ断面図
FIG. 3 is a lens sectional view of Numerical Example 3 of the attachment lens of the present invention.

【図4】 本発明のアタッチメントレンズの数値実施例
4のレンズ断面図
FIG. 4 is a lens sectional view of Numerical Example 4 of the attachment lens of the present invention.

【図5】 本発明のアタッチメントレンズの数値実施例
1の収差図
FIG. 5 is an aberration diagram of Numerical Example 1 of the attachment lens of the present invention.

【図6】 本発明のアタッチメントレンズの数値実施例
2の収差図
FIG. 6 is an aberration diagram of Numerical example 2 of the attachment lens of the present invention.

【図7】 本発明のアタッチメントレンズの数値実施例
3の収差図
FIG. 7 is an aberration diagram of Numerical example 3 of the attachment lens of the present invention.

【図8】 本発明のアタッチメントレンズの数値実施例
4の収差図
FIG. 8 is an aberration diagram of Numerical example 4 of the attachment lens of the present invention.

【図9】 本発明のアタッチメントレンズを装着する撮
影レンズのレンズ断面図
FIG. 9 is a lens cross-sectional view of a taking lens to which the attachment lens of the present invention is attached.

【符号の説明】[Explanation of symbols]

AL アタッチメントレンズ L1 第1群 L2 第2群 ML 撮影レンズ d d線 g g線 S.C 正弦条件 ΔS サジタル像面 ΔM メリディオナル像面 AL Attachment lens L1 First group L2 Second group ML Photographing lens d d line g g line S.I. C Sine condition ΔS Sagittal image plane ΔM Meridional image plane

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 撮影レンズの像面側に着脱自在に装着
し、該撮影レンズの有効画角サイズより小さい有効画角
サイズのカメラに装着可能なマウント変換のための負の
屈折力のアタッチメントレンズであって該アタッチメン
トレンズは正の屈折力の第1群と負の屈折力の第2群よ
り成り、該第1群は正レンズ1枚から成り、該第2群は
負レンズと正レンズの2枚のレンズから成り、該アタッ
チメントレンズの拡大倍率をβとするとき、 1<β<1.1 なる条件を満足することを特徴とするアタッチメントレ
ンズ。
1. An attachment lens with a negative refractive power for mount conversion, which is detachably mounted on the image plane side of a taking lens and is mountable on a camera having an effective angle of view smaller than the effective angle of view of the taking lens. The attachment lens is composed of a first group having a positive refractive power and a second group having a negative refractive power, the first group is composed of one positive lens, and the second group is composed of a negative lens and a positive lens. An attachment lens comprising two lenses and satisfying a condition of 1 <β <1.1 when a magnification of the attachment lens is β.
【請求項2】 前記第1群と第2群の焦点距離を各々f
1,f2、該第1群と第2群の面間隔をD12、前記ア
タッチメントレンズの焦点距離をfaとしたとき、 1.2<|f1 /f2|<1.6 0.002<|D12/fa|<0.01 なる条件を満足することを特徴とする請求項1のアタッ
チメントレンズ。
2. The focal lengths of the first lens unit and the second lens unit are f
1, f2, the surface distance between the first and second groups is D12, and the focal length of the attachment lens is fa: 1.2 <| f1 / f2 | <1.6 0.002 <| D12 / The attachment lens according to claim 1, wherein the condition fa | <0.01 is satisfied.
【請求項3】 アタッチメントレンズを構成する正レン
ズの材質の平均屈折率と平均アッベ数をそれぞれnp
νp 、負レンズの材質の屈折率とアッベ数をそれぞれn
n ,νn とするとき、 1.0<nn /np <1.2 1.0<νn /νp <1.2 なる条件を満足することを特徴とする請求項1のアタッ
チメントレンズ。
3. The average refractive index and the average Abbe number of the material of the positive lens constituting the attachment lens are n p and
ν p , the refractive index and Abbe number of the negative lens material are n
n, [nu when the n, 1.0 <n n / n p <1.2 1.0 <ν n / ν p of attachment lens according to claim 1, characterized by satisfying the <1.2 condition: .
JP32139993A 1993-11-26 1993-11-26 Attachment lens Pending JPH07151965A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP32139993A JPH07151965A (en) 1993-11-26 1993-11-26 Attachment lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP32139993A JPH07151965A (en) 1993-11-26 1993-11-26 Attachment lens

Publications (1)

Publication Number Publication Date
JPH07151965A true JPH07151965A (en) 1995-06-16

Family

ID=18132118

Family Applications (1)

Application Number Title Priority Date Filing Date
JP32139993A Pending JPH07151965A (en) 1993-11-26 1993-11-26 Attachment lens

Country Status (1)

Country Link
JP (1) JPH07151965A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11311739A (en) * 1998-04-28 1999-11-09 Asahi Optical Co Ltd Telescopic objective lens system
KR20030008835A (en) * 2001-07-20 2003-01-29 최대일 A subminiature lens system
JP2011070208A (en) * 1999-11-12 2011-04-07 Bh Image Co Llc Imaging device allowing capturing of image of view at different resolution
USRE44087E1 (en) 1996-06-24 2013-03-19 B.H. Image Co. Llc Presenting panoramic images with geometric transformation
US9784954B2 (en) 2015-01-30 2017-10-10 Samsung Electronics Co., Ltd. Rear conversion lenses

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE44087E1 (en) 1996-06-24 2013-03-19 B.H. Image Co. Llc Presenting panoramic images with geometric transformation
JPH11311739A (en) * 1998-04-28 1999-11-09 Asahi Optical Co Ltd Telescopic objective lens system
JP2011070208A (en) * 1999-11-12 2011-04-07 Bh Image Co Llc Imaging device allowing capturing of image of view at different resolution
KR20030008835A (en) * 2001-07-20 2003-01-29 최대일 A subminiature lens system
US9784954B2 (en) 2015-01-30 2017-10-10 Samsung Electronics Co., Ltd. Rear conversion lenses

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